Rocket decelerated mine



Allg 26, 1958 D. Q. BRUMBAUGH ROCKET DECELERATED MINE Filed OCl'.. 15,1954 NN N ml nl 1mi NQ .Nd-m

INVENTOR D. Q. BRUMBAUGH ATTORNEYS mm hm g @234g 91mg 2,848,945 PatentedAug. 26, 1958 ROCKET DECELERATED MINE Donald Q. Brumbangh, Hyattsville,Md., assignor to the United States of America as represented by theSecretary of the Navy Application October 15, 1954, Serial No. 462,635

3 Claims. (Cl. 102-7) (Granted under Title 3S, U. S. Code (1952), sec.266) The invention described herein may be manufactured and used by orfor the Government of the United States of America for governmentalpurposes without the payment of any royalties thereon or therefor.

'I'he present invention relates to a device for decelerating a mine andmore particularly to a device for reducing the forward velocity of amine whereby the mine may enter the water without damage thereto or tothe delicate mechanism contained therein when launched at high or lowaltitudes from a fast moving aircraft.

More specifically, the invention relates to a decelerating device foruse in an aerial launched mine in which the decelerating force isproduced by a rocket motor mounted in the nose of the mine and whichincludes fuze means operated as the mine is dropped from the aircraft inight for initiating the rocket motor when the mine is a predetermineddistance from the surface of a body of Water thereby to reduce thevelocity of the mine prior to entrance of the mine into the water.

The parachute method heretofore used for decelerating a mine during amine planting operation has not proven entirely satisfactoryparticularly when the mine was released from high altitudes and a directopening chute was employed for the reasons that the chute caused themine to drift of course due to the various aerodynamic forces actingthereon and thus preventing accurate planting of the mine in the desiredarea and the delayed opening type parachute method required complicatedcontrol devices and equipment which at times proved unreliable.

The present invention overcomes the disadvantages heretofore encounteredby providing a new and improved rocket decelerating device which isdevoid of cumbersome parachute packs and fragile control devices wherebythe mine may be accurately planted in the desired area and the forwardmotion of the mine is invariably retarded as lthe mine approaches thesurface of the body of water.

An object of the invention is to provide a new and improved rocketdecelerating device for an aerial launched mine.

Another object of the invention is the provision of a rocketdecelerating device which may be readily installed in a conventionalmarine mine for reducing the forward velocity of the mine .after themine is launched from a fast moving aircraft.

A further object of the invention is to provide a mine decelerationdevice in which the decelerating force is produced by a rocket motoractuated as the mine approaches the surface of a body of water after themine is dropped from an aircraft in ight.

A further object of the invention is to provide a mine decelerationdevice constructed and arranged to reduce the velocity of the mine inpredetermined time delayed relation with respect to impact of the minewith the surface of la body of water thereby to prevent damage to themine and the mine control mechanism contained therein as the mine entersthe water.

A still further object of the invention is the provision of a rocketdeceleration device for au aerial launched marine mine wherein adischarge jet of a rocket motor operated in time delayed relation withrespect to the release of the mine from an aircraft in flight thereby toreduce the forward velocity of the rnine prior to entrance of the mineinto a body of water.'

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawing wherein:

Fig. 1 is an elevational view of a mine partially broken away andpartially in section illustrating a preferred embodiment of the presentinvention attached to a marine mine;

Fig. 2 is a view similar to Fig. 1 illustrating an alternate arrangementof the device of Fig. l; and

Fig. 3 is a fragmentary sectional view of a mine illustrating anotheralternate arrangement of the device of Fig. l.

vReferring now to the drawing wherein like characters of reference areused to designate like parts throughout the several views and moreparticularly to Fig. 1 thereof, the numeral 10 generally indicates themine. The mine comprises a casing 11 having a stabilizing assembly 12secured to one end and a centrally disposed tubular member 13 formed onthe other end thereof enclosed by the mine casing 11 and providing awell 14 within the leading end or nose of the mine casing.

The deceleration device consists essentially of a rocket motor 15 and afuze 16, as illustrated, the aforesaid elements are disposed within thewell or recess 14 and arranged along the longitudinal axis of the minecasing.

The motor 15 comprises a tube 17 secured to the mine casing 11 as at 18by threaded engagement therewith and having propellant charge 19therein. A nozzle 20 is disposed within the tube 17 at the nose end ofthe mine and a squib 21 and igniter 22 is disposed within the tube andarranged at one end of the propellant charge 19. It will be noted thatthe fuze 16 is releasably mounted in the forward end of the tube 17 by apair of resilient elements 23 disposed about the fuze casing and infrictional engagement with the tube 17, the fuze being electricallyconnected to the squib 21 by a pair of conductors 24.

The fuze 16 may be a well known conventional VT type fuze such, forexample, as the type which is actuated by reections of a radio signaltransmitted therefrom and from the water or land when the mine is apredetermined distance from the surface thereof. The fuze, however, isrendered operable as the arming wire 25 is withdrawn therefrom,withdrawal of the arming wire occurring as the mine is released from anaircraft and falls away therefrom. When this occurs, the fuze is in acondition to be operated in response to water reflections thereby tosupply an electrical firing impulse to the squib 21 by way of conductors24. Moreover, the fuze 16 is constructed and arranged to initiate therocket motor when the mine is a predetermined distance from the surfaceof the body of water such, for example, as from 500 to 1000 feet.

Upon firing of the squib 21 in the aforesaid manner, the igniter 22 isignited which, in turn, ignites the propellant charge 19. It will beunderstood that when the propellant 19 is ignited, the fuze 16 isforcibly ejected from the motor tube 17 by the force of the jetdeveloped and discharged through nozzle 20. Thus as the rocket motoroperates the resulting action creates a substantial backward thrust toslow the forward velocity of the mine sufliciently to permit the mine toenter the water without damage thereto.

If desired, a pair of slip connectors may be provided on the pair ofconductors 24 respectively at the squib end of the motor to detachablysecure the conductors thereto whereby the conductors may be carriedalong with the fuze as the fuze is forcibly ejected from the motor tube17 1n the aforesaid manner. Furthermore, suitable insulating material 30is disposed between the tube 17 and tubular elementlS thereby to`heatinsulatethe motor. s

from the main charge 26 whereupon iringrof the main charge by the heatdeveloped as the propellant is ignited and burns is prevented.

Referring now to Fig. 2, the arrangement shown thereon is particularlyadapted for use in mine planting operations at low altitudes such, forexample, as at 20G feet and comprises a fuze generally indicated by thereference character 2'7; It will be noted that the mine, rocket motorand fuze retaining elements are identical to the structure shown in.Fig.l and thus like reference characters are employed to designate such likeparts.

The fuze 27 illustrated on Fig; 2 is a percussion red and delayed typefuze and comprises a casing 28 releasably held in the nose end of themine by the resilient elements 23. A delay element 29 and flash charge31 is disposed within one end of the casing 28, the flash charge havingone end of a quick burning pyrotechnic fuze 32 connected thereto, theother end of the fuze being connected to the squib 2l. A spring actuatedtiring pin 33 is releasably held in an initial safe position by thearming wire 25, the wire being withdrawn to release the firing pin inthe manner heretofore set forth. When this occurs, the firing pin isforcibly driven into firing engagement with the delay element 29 by thespring 33' whereupon the delay element is fired. After a predeterminedperiod of time has elapsed the delay element fires the ash charge ,3lwhich ignites the quick burning fuze 32'thereby tiring the squib 2l. Thesquib ignites the igniter 22 which ignites the propellant 19 whereuponthe fuze 27 is forcibly ejected from the motor tube 17 and thus therocket motor will operate in the same man- Iner as heretofore set forthto retard the forward motion of the mine.

In the arrangement of Fig. 3, the fuze is generally indicated by thereference character 34 and comprises casing 35 releasably secured withinthe motor tube 17 in like manner to fuzes lo and 27. The fuze 34 ispreferably a mechanical delay type fuze which is rendered operable asthe arming wire Z is withdrawn therefrom and may include either asuitable clock mechanism of any well known type such, for example, asthe type of clock mechanism employed in an automatic electric toaster ormotor means having a reduction gear arrangement for actuating the Switch35 from a normally open position to a closed position in predeterminedtime delayed relation withV respect t'o the release of the mine from theaircraft by movement of the switch actuating rod 39 as the arming wire25 is withdrawn. The switch comprises a pair of contacts 36 and 37normally engaging a sleeve 3S .mounted on the switch actuating rod 39and composed of any insulating material suitable for the purpose. VBythis arrangement, the switch is normally openY and will remain openuntil the rod 39 is moved axially toward the trailing end of the mine bythe aforesaid mechanisms. lt will be understood that as the rod 39 ismoved, contacts 3io-37 are brought into engagement with the rod which iscomposed of conducting material. When this occurs, the ring `circuit 41connected to the squib 21 and including contacts 36-37 and a battery Bis rendered effective thereby to re the squib which ignites the igniter22 and thus the rocket motor is set in operation whereupon the resultingaction forcibly ejects the fuze 34 from tube 17 and creates asubstantial `backward thrust to slow the forward velocity of the mine.

Brieiy stated in summary, the present. invention contemplates theprovision of a new and improved deceleration device for an aerialplanted marine mine for reducing Vthe forward velocity of the mine afterthe minehas been released from the aircraft and a predetermined periodof time before the mine enters a body of water.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that Within the sco-pe of the appended claims the inventionmay be practiced otherwise-than as specifically described.

What is claimed as new and desired to be secured by Letters VPatenteofthe United States is:

l. A decelerating device for a mine adapted to be dropped from anaircraft in flight comprising, in combination, a mine casing having acentrally disposed well formed therein and opening in the nose portionthereof, a rocket motor disposed with-in said well, a fuze disposedwithin saidwell, means including a normally open tiring circuitconnected to said motor and fuze for igniting said rocket motor as saidring circuit is closed, normally open switch; means 'carriedby said fuzeandincluded in said tiring'circuit for closing said tiring circuit,

a movable rod having a contact element carried thereby' for closing saidswitch means as the rod is movedlongif tudinally from anY initial lockedposition to a moved yposition, an arming wire releasably connected tosaid rodfor locking the rod in said initial position until the armingwire is disconnected therefrom, and a time delay actuating mechanismconnected to said rod for moving` the rod to said moved position when apredetermined` period of time has elapsed after the arming wire has beendisconnected.

2. A device fordecelerating the forward velocity-,of an I aeriallaunched mine as the mine approaches the surface of a body of watercomprising, in combination, a mine` casing having an axially disposedwall integral with said casing and forming a well within the casing, acontainer disposed within said well in threaded engagement withsaidcasing and in uniform spaced relation with respect to said wall, arocket motor having a propellant charge disposed within said container,an igniter arranged within said container for igniting said propellantcharge as the igniter is ignited, a perCussive fuze disposed Within andreleasably sealed in one end of the well and adapted to be forciblyejected therefrom by the products of combustion of the propellant chargeas the charge is ignited, a

pair of mutually spaced annular grooves formed in said f wall, a pair ofcomplementary grooves formed in'said fuze, a pair of mutually spacedannular resilient elements disposed within said grooves in the wall andfuze respectively for releasably sealing said fuze within the well, a

firing pin carried by said fuze, means for actuating said 1 firing pinto a tiring position as the mine is released from an aircraft in flight,a pyrotechnic delay element carried'.

by sai-d fuze and ignited by said tiring pin, a pyrotechnic flash chargecarried by said delay element and ignited thereby, a quick 'burningelongated pyrotechnic fuze having one end connected to said flash chargeand the otherV end thereofconnected to said igniter and ignited by saidash charge for igniting saidv igniter when a predetermined period oftime corresponding to said delay has elapsed thereby to ignite saidpropellant charge when the mine is a predetermined distance above thesurface of the aerial launched mine asy the mine approaches the surfaceof 4a body of water comprising, in combinationa mine casing having-anaxially disposed wall integral with said,V

casing and forming a well within the casingga container disposed withinsaid wellA ,in threaded engagementwith saidwall and 4in uniform spacedrelation, with respect to said wall, a 'rocket motor disposed withinsaid container, an igniter arranged within the container for ignitingsaid rocket motor, an electrical fuze disposed within and releasablysealed in one end of the well and adapted to be forcibly ejectedtherefrom by the products of combustion ofthe motor as the motor isignited, means including a pair of mutually spaced resilient elementscarried by said fuze in engagement with said wall for releasably sealingthe fuze in saidrwell, a source of electrical energy arranged within thefuze, a normally open tiring circuit connected to said igniter and saidsource for gniting said igniter as said circuit is closed, a rodcomposed of electrical conducting. material arranged within said fuzeand movable axially from an initial position to a moved position, asleeve composed of insulating material mounted on said rod, a pair ofcontacts included in said firing circuit normally in engagement withsaid sleeve for closing the ring circuit as the sleeve is moved lby saidrod an amount suieiently to move the contacts out of engagement with thesleeve and into engagement with said rod, and a clock time delayactuating mechanism arranged within said fuze, for moving said rod fromsaid initial position to said moved position a predetermined period oftime after the mine has been dropped from an aircraft in Hight.

References Cited in the file of this patent UNITED STATES PATENTS1,311,740 Asbury July 29, 1919 1,483,864 Borden et al. Feb. 19, 19241,884,125 Murrow Oct. 25, 1932 2,101,082 Mathsen Dec. 7, 1937 2,693,327Hild Nov. 2, 1954 FOREIGN PATENTS 554,733 Great Britain July 16, 1943

